Oral Health Group
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Learning Assessment (July 01, 2001)

July 1, 2001
by Oral Health


The SLSA program is based on current, referenced literature and consists of 40 questions, answers, rationales and references. Answers appear at the end of each quiz.

Dentists who complete the 15 question quiz in the November, 2001 issue of Oral Health may be eligible to receive continuing education points. The names and license numbers of all who complete the quiz will be forwarded to their respective provincial licensing authorities.

QUESTION 25

Following root canal therapy, filling material extruded through the apex may

1. produce paraesthesia.

2. be associated with a defective seal.

3. produce pain.

4. slowly disappear.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above

Rationale

Experimental data have shown that material extruded into the apical periodontal space results in the necrosis of the periodontal ligament and bone resorption adjacent to the material. Extruded material does not necessarily prevent periapical healing, but is often associated with a defective apical seal. Extruded material may slowly disappear, with a return to a normal radiographic appearance. The reaction can be mild, but it can also be serious, particularly in the case of mandibular premolars and molars if filling material finds its way into the mandibular canal. If this occurs, persistent pain, hyperaesthesia, and paraesthesia can result. Some materials are neurotoxic; others, because of their expansion upon setting, can cause nerve compression.

If N2 and paraformaldehyde materials are extruded into the mandibular canal, they must be removed as soon as possible. With other materials healing is unpredictable and other factors should be considered before intervening surgically. If nerve compression is suspected, surgical intervention is required to remove the material and decompress the nerve. Nerve compression, left untreated, results in Wallerian degeneration and necrosis of tissues.

Measures must be taken toward selecting the least toxic filling materials and using all materials in a controlled manner. Cases with overextended root fillings should be carefully observed.

REFERENCES

1. Gunraj, M.N., West, N.M. Assessment of endodontically treated teeth for restorative procedures. Compend Contin Educ Dent. 11(7), 1990.

2. Neaverth, E.J. Disabling complications following inadvertent overextension of a root canal filling material. J Endod 15:135-139, 1989.

QUESTION 26

Where an alveolar ridge is inadequate, augmentation should precede implant placement.

Dehiscence recession can be treated with a free autogenous graft.

A. The first statement is true, the second is false

B. The second statement is true, the first is false.

C. Both statements are true.

D. Both statements are false.

Rationale

Where alveolar tissue is lost after extraction, ridge augmentation techniques are used to restore the reduced area. In the case of a soft tissue inadequacy, management of the problem consists of harvesting a connective tissue graft from the palate and suturing this to the underlying periosteum. Where an implant is to be used, the ridge augmentation can take place during the implant placement if sufficient bone for the implant is present. In a patient with inadequate bone, augmentation must be completed before the implant is inserted.

Dehiscence recession can be dealt with by a pedicle flap but, in recent times, a free autogenous graft of connective tissue from the palate (with the epithelial component removed) is inserted into an envelopelike pouch at the recipient site. This would appear to provide the most stable result.

REFERENCES

1.Pasquinelli, K.L. Periodontal plastic surgery. J Calif Dent Assoc 27:597-610. 1999.

2.Evian, C.J., Karateew, E.D., Rosenberg, E.S. Periodontal soft tissue considerations for anterior esthetics. J. Esthetic Dent 9:68-75. 1997.

QUESTION 27

The use of an implant in the anterior maxilla is dictated by the

1. local bone anatomy

2. prosthetic superstructure

3. esthetics

4. patient’s health.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above

Rationale

Although there are several options available for the replacement of missing teeth in the anterior maxilla, a fundamental demand in all situations is aesthetics. Ideally, implant position should be determined primarily by the planned future prosthesis and not by local bone anatomy alone. As the implant should represent the apical extension of the prosthetic superstructure and not the opposite, the term “restoration driven” rather than “bone driven” implant placement becomes the necessary approach. This implies a precise three-dimensional implant positioning permitting appropriate emergence profile. If an optimum stable aesthetic and functional result has to be achieved, lateral bone augmentation procedures, as well as soft tissue grafting, may be required. In all of these choices, the patient’s needs, expectations, general health condition, as well as the socio-economic profile require to be taken into account for a satisfactory treatment outcome.

REFERENCE

Belser, U.C., Buser, D., Hess, D., et al. Aesthetic implant restorations in partially edentulous patients-a critical appraisal. Periodontology 2000, 17:132-150, 1998.

QUESTION 28

On eruption, permanent central incisors show evidence of fluorosis. You would expect that this developed at the age of

A. 12-14 months

B. 15-18 months

C. 22-25 months

D. 30-36 months

Rationale

The primary dentition is thought to be completely formed before the end of the first year of life, whilst the critical period for fluorosis development in the permanent central incisors is estimated at 22-25 months of age.

A major study by Milsom (1996) showed that primary tooth fluorosis was only weakly predictive of fluorosis in the permanent dentition. It should be noted that while fluorosis of both dentitions share a fundamental etiology, i.e., excessive fluoride ingestion during tooth formation, the specific sources of fluoride ingested during formation of primary teeth may be quite different from those during permanent tooth development.

REFERENCES

1. Warren, J.J., Kanellis, M.J., Levy, S.M. Fluorosis of the primary dentition: what does it mean for the permanent teeth? JADA 130: 347-356, 1999

2. The Oral Care Report Vol. 5, No. 4, 1995 Ed. G. Nikiforuk.

Answers for June 2001 SLSA questions:

21. B 22. A 23. A 24. E

Funding for the SLSA program has been provided by: